To recreate the position of
the sun in the viewfield of a driver in the moments prior
to a collision.

Background:

An eastbound fuel tanker truck
collided with the rear of a school bus stopped at a
pick-up location on an early December morning. The sun's
low position in the eastern sky blinded the truck driver
as he negotiated a sweeping right turn, from eastbound to
south-east-bound, on an 80 kph stretch of highway. The
turn brought the stationary bus directly in line with the
sun, which was momentarily shielded by a large pine tree.
As the sun "re-appeared" from behind the tree,
the sun and bus were directly in line. Shade from an
existing forest contributed to a prolonged icy glaze over
the highway in the vicinity of the bus. Evasive action by
the truck driver was delayed due to visibility conditions
(i.e. sun blinding) and hampered due to road conditions
(i.e. icy glaze on the shaded portion of highway).

Methodolgy:

The two photos below demonstrate
how the scene was re-created from the vantage point of
the truck driver. They are samples of a series of 13 that
were taken at the accident scene. The photos were taken
at the driver's eye height in 100-foot intervals along
the highway prior to the point of impact (POI). The
location of the school bus was determined from the police
accident report.

The accident scene was surveyed
using total station survey equipment. From this survey
data, a 3D computer model of the terrain was generated
into which the sun's position was inserted using software
developed by R. Bouwmeester & Associates. The next
step involved creating "driver's eye perspective
views" within the 3D model. These views were created
to match the driver's vantage point as depicted in each
of the photos taken at the 100-foot stations. In the
final step we superimposed the computer-generated wire-frame perspective views into each of the photos. Two
samples, depicting the views at 800 feet and 400 feet
prior to impact, are shown.